Hi all,

I have a 2015 A6 TDI Ultra. A few months ago the battery really started to struggle in the colder mornings. Considering it was the original battery I swapped it out for a new one. However as much as it starts ok, it wasn’t cranking very well still. So as time has gone on I’ve just sort of lived with it, but the other day as I was heading back to the car, I heard the electronic handbrake engage and disengage a couple of times. The car was switched off and had been for around 20mins, which leads me to believe this is what’s causing the drained battery in the mornings. It has no fault codes or dash warnings. Has anyone else experienced this at all?

Thanks

Hello Stuart,

Many thanks for being in touch with the forum.

It seems as if the car could indeed be suffering from a parasitic drain, and if this were mine, I would be getting that checked by an autoelectrician (rather than a local garage). Be aware, that the draining current, should be assessed at least a couple of minutes after the car has been locked down and the alarm has fully set. Drains of around 50mA would be expected - anything much more is undesirable. 
Having said that, battery condition is king with these modern cars, as is of course the alternator output, to ensure it’s kept fully charged. 
New battery? - absolutely the correct AGM type for the car?? Make as a matter of interest. 
Kind regards,

Gareth.